Development of atherosclerotic-like lesions in the sand rat (Psammomys obesus)

Abstract

The desert rodent (Psammomys obesus), which has been shown to develop maturity-onset diabetes mellitus on a diet of rat chow, was found to develop atherosclerotic lesions in the cardiovascular system when fed a 5% cholesterol diet for 6 months. The animals in this study developed a seven-fold increase in blood cholesterol levels within the first month on the cholesterol diet; the blood levels of cholesterol remained high throughout the 6-month study. Aortic valve lesions, composed of collagen and increased numbers of intimal cells containing neutral fat and cholesterol, were significantly increased in severity and in the number of animals exhibiting the lesions (P<0.001) over the period of observation. Similar changes in the aorta and coronary arteries were also noted. This is a new rodent model of diet-induced atherosclerosis in which the course of development of the lesions can easily be observed.